Yep, also these
http://buffalo.craigslist.org/for/275740796.html
and
http://www.fatwallet.com/forums/messageview.php?catid=18&threadid=699179
If your willing to pay
http://www.uline.com/
Or any local store like office depot/max should have a similiar size or a size larger you can shop a few inches here and there.